Aspirator: Description and Operation

Measuring Passenger Compartment Temperature, Purpose
The interior sensor aspirator fan in the overhead control panel control module is actuated via the interior CAN bus (CAN B) at the request of the pushbutton control module. A diagnosis check is first performed on the sensor aspirator fan.

Then the overhead control panel control module signals the status and the measured interior compartment temperature to the pushbutton control module via the interior CAN bus (CAN B). Under certain operating conditions the pushbutton control module requests that the the blower be switched on even when the ignition is switched off. (e.g. residual engine heat utilization).